I write a lot of content on a daily basis, and I have a lot of menus, submenus etc. I don't want to use the menu gui each time I create a new page/article.
Is there any plugin or way of automatically putting the pages into the specified submenus?
I believe this plugin will do what you're looking for: Add Descendants as SubMenu Items
I'm not sure if it will handle posts / categories but for pages it's good.
Hope this helps, best of luck!
We have been accomplishing the same task with the Gecka Submenu plugin. Works like a charm.